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I wonder if the slight slowdown is something to do with the graph below.(The graph is based on SLC with 100K PE).

Either way, I can't wait to find out what happens when the NAND can no longer erase or hold a change. If the NAND can't erase how can it hold a charge? What happens when data can no longer be erased or loses it's charge? Will the OS become unstable? Will SMART pop up with a warning and then render the drive read only?

Very interesting that the wear range delta for the SF-1200s with no static data is so much worse than with static data. I know with mine it got to 8 when I had no static data and dropped down to 3 (and has since stayed there) once I added ~35GiB of static data.

With yours, SynbiosVyse, wear range delta has been climbing steadily the entire time (up to 23 now) and you have very little static data.

One would expect wear range delta to be higher with static data but the opposite is true so far. My SF-1200 is ~63% full with static data and my wear range delta shrunk when I added it. You have nearly 0 static data and yours continues to grow. With static data, NAND seems to be evenly used; without static data, NAND doesn't seem to be evenly used.

It's almost like it expects static data as it tries to do wear leveling.

Hard to know the effects of wear range delta...we don't know the units. Is it a percentage between 90th percentile usage and 10th percentile usage? Is it P/E cycles difference between 99th percentile usage and 1st percentile usage? If it's just P/E cycles between most used and least used, a difference of 23 cycles between least and most isn't a big deal when the average is 688 (as yours is now). If it's 23% wear difference between most/least, that's pretty notable and probably will have an effect on endurance. If it's 23% difference between 90th and 10th percentile, that could be really bad for endurance.

Also of note from your F40-A, LTT hasn't kicked in yet even though ~20% of your NAND's minimum rated lifetime has been used in less than a dozen days. Seems lifetime was set for something very short, maybe even impossibly short (basically deactivating LTT). And even if it kicks in, write speeds may not drop that much.

With static data, NAND seems to be evenly used; without static data, NAND doesn't seem to be evenly used.

This seems counter-interuitive to me. If you have static data, wouldn't the NAND be unevenly used since some of the drive is dormant, hence, lower wear range delta? There will be a portion of the drive undergoing very few, if any, P/E cycles.

If you don't have static data, the drive will be evenly used because it is utilizing practically the whole drive.

This seems counter-interuitive to me. If you have static data, wouldn't the NAND be unevenly used since some of the drive is dormant, hence, lower wear range delta? There will be a portion of the drive undergoing very few, if any, P/E cycles.

If you don't have static data, the drive will be evenly used because it is utilizing practically the whole drive.

If I remember correctly the delta between most-worn and least-worn was higher on the V2 when I used static data and it remained lower on the V3 with no static data. SF drives rotate static data, so presumably that would increase WA.

The really weird thing though is that the drive has not hit LTT.

Could you please run Anvil's app on 100% incompressible data just to make sure LTT has not kicked in and is being masked by compression. I'm sure write speeds would have dropped if LTT had kicked in, although at 46% it would not be by as much as I saw.

This is a retail drive?

Off topic a bit, but I've noticed that one of my Intel drives has gone from 98% back to 100% over the 12 months or so that I switched it out from being an OS drive to a drive that just contains static data. Quite strange, but it has definitely reverted back to 100%.

Off topic a bit, but I've noticed that one of my Intel drives has gone from 98% back to 100% over the 12 months or so that I switched it out from being an OS drive to a drive that just contains static data. Quite strange, but it has definitely reverted back to 100%.

This seems counter-interuitive to me. If you have static data, wouldn't the NAND be unevenly used since some of the drive is dormant, hence, lower wear range delta? There will be a portion of the drive undergoing very few, if any, P/E cycles.

If you don't have static data, the drive will be evenly used because it is utilizing practically the whole drive.

I don't have a good explanation, I'm just translating what the data says and it says with static data, NAND seems to be evenly used; without static data, NAND doesn't seem to be evenly used.

I don't think any modern SSD doesn't actively rotate static data, however; it's extremely important for wear leveling. Even the 'old' Indilinx M225->Vertex Turbo has its reported wear range (based on max, average, and min reported P/E cycles) stay fairly constant over time....the Max Wear started at 255 cycles above Avg (257 vs. 2) and now Avg is at 2809 and Max is just 332 cycles higher than that.

Originally Posted by Ao1

SF drives rotate static data, so presumably that would increase WA.

I think that's exactly what's going on.

With my compression tests I observed a WA of .732x with the 46% setting with no static data and 12GiB free. With the 46% setting, 34.85GiB of static data, and 12GiB free WA has been .782x. With the F40-A with no static data and 1GiB free, it's been .803x. So the F40-A has the highest WA and a growing wear range delta--maybe it's the 1GiB free setting?

Originally Posted by Ao1

The really weird thing though is that the drive has not hit LTT.

Could you please run Anvil's app on 100% incompressible data just to make sure LTT has not kicked in and is being masked by compression. I'm sure write speeds would have dropped if LTT had kicked in, although at 46% it would not be by as much as I saw.

Agreed that it's very odd LTT hasn't activated yet. But the F40-A has been writing to NAND at 47.1MiB/sec, so I really doubt LTT will be hiding behind compression considering the NAND write speed is high and unchanged